The transalveolar sinus elevation,
often called closed or also osteotome technique
is based on a technique developed by Summers
and published in the early 90s.
Summers used a set of sharp osteotomes
of increasing diameter in order to
create a controlled fracture of the sinus floor and
consequently push bone debris from the sides of the osteotomy
to an apical direction,
creating the space necessary under the sinus membrane
in order to place implants.
Ever since the publication of Summers however,
there has been so many modifications and changes
introduced to the transalveolar technique
that today it is difficult to identify a single standard.
The basic principle however remains the same:
the creation of a controlled fracture of the sinus floor
and the creation of a space under the membrane
with or without the use of grafting material.
There is a wide variety of osteotomes available today,
either as generic instruments
or specific to certain systems and techniques.
Nevertheless, some critical elements of osteotomes have to do with
the type of the edge and the shape
of the engaging part of the instrument.
A concave edge is more aggressive
and will concentrate more force on a smaller surface.
It is indicated in cases of harder cortical bone,
but will require precise control.
When using this type of instrument
after the preparation of the osteotomy,
the force is gathered at the margins of the osteotomy
and often pushes the fractured segment of the sinus floor
to an apical direction.
A convex edge of the osteotome is less
aggressive and safer to use in cases of softer bone.
Such an edge is more likely to create
a less defined dome-like fracture of the sinus floor
and it is usually safer than the concave edge.
Furthermore, the engaging part of the osteotome
can be either parallel or tapered.
A tapered instrument will condense the bone laterally
at the same time as advancing
in an apical direction.
This can be beneficial in cases of soft spongious bone.
Now let's take a quick overview of
how this could be applied in a typical patient case.
Our patient is going to receive two implants
in a segment of his posterior maxilla.
After the three-dimensional radiographic assessment,
we have calculated that
the bone height to the sinus floor
is 6 and 4 mm, respectively.
Let's see the implant in the 6 mm site first.
Here we are looking to generate
two more millimetres from the sinus.
To start with, we identify the place of the osteotomy
and then, we continue preparing the osteotomy
Nikos MattheosClinical Associate Professor in Implant Dentistry
